So if you're only roasting once or twice a year, we say skip buying a roasting pan and see if one of these alternatives will work for you instead. The big advantage of a roasting pan is that it's big, literally. A standard roasting pan can fit a 16-pound turkey with no problem. But many of us don't actually need to be roasting a 16-pound turkey, and a smaller turkey will fit quite easily in some of the cookware we already have.
The rule of thumb is that you want to be able to sit on your ball with your legs at a 90-degree angle or slightly more, but not less. Use these guidelines when you buy a fitness ball: If you are 4'11 - 5'4, get a ball that is 55cm. If you are 5'5 - 5'11, get a ball that is 65cm.
Beginners to the exercise can start with a 6 or 8 pound ball, more advanced exercisers can start with a 14, 16, 18 or 20 pound ball. Stand with your feet shoulder width apart, facing a wall and holding the medicine ball at your chest. Pul your shoulders back and keep your chest up high.